Dental Amalgam Fillings: Materials, Process, Benefits, And More

Dental Amalgam Fillings

Amalgam fillings, now considered a standard care solution for dental restoration, have more than two hundred years of history. Auguste Taveau, a French dentist, came up with an amalgam of melted silver and mercury in 1816 and used the same for dental restoration. 

The practical problems in these fillings were solved when “Edward Crawcour and his nephew Moses” introduced amalgam filling in the USA in 1833. 

Since then, dental amalgam fillings have come a long way and have undergone a lot of evolutions. Further, despite multiple debates about the use of mercury in these fillings, these are declared safe by the FDA and the American Dental Association.

The Centers for Disease Control and Prevention also has declared that it has not found enough evidence to prove the toxic effect of mercury used in amalgam fillings.

Do you want to know about amalgam fillings, how they are placed, their benefits, drawbacks, and more? Here is a complete guide for you.

What Are Dental Amalgam Fillings?

Dental amalgam fillings, classified as Class II medical devices by the FDA, are restorative solutions to fix tooth decay and cavities. 

Dental amalgam fillings are a mixture of many metals, among which mercury and silver are the major components. These fillings resemble the look of silver material and are popularly known as silver fillings.

However, the FDA does not approve of calling these fillings silver fillings as the term does not justify the overall composition of the amalgamation.

These fillings are now available in the form of capsules, which are put in a machine to make the mixture in the form of a solid paste. The paste is then applied in the cracked/decayed part of a tooth or inside the cavity for filling. 

Dental amalgam fillings are single-visit treatments, and the thick paste starts getting hard within three to eight minutes of application. 

Based on the amalgam filling used, the location of the filling, and the size of the decay, the filling will take around one to three days to set completely. 

What Are The Materials Used In Silver Amalgam Fillings?

Dental amalgam fillings are made with elemental mercury and a metal alloy powder in a 1:1 ratio. To explain further, these amalgam fillings have 50% elemental mercury, 35% silver, 15% tin or tin and copper mixture, and a little bit of zinc. 

Mercury makes the fillings stronger by binding all the particles together, while silver offers added strength and corrosion resistance to the fillings. Copper is mixed with tin in these amalgams so that tin does not get contracted or expanded easily and causes no difficulty setting up the fillings.

Zinc in the composition prevents oxidation of all other metals present in the fillings so that they remain tarnish-free for longer. 

How Are Dental Amalgam Fillings Done?

The most intriguing part of placing dental amalgam fillings is preparing the compound. At first, I will explain how it is made and then get into the step-by-step procedure of placing the fillings.

Preparing Dental Amalgam Fillings

The components for making dental amalgam fillings come in the form of capsules. These capsules have two chambers. One chamber of the capsule is filled with elemental mercury, and the other half has the alloy mixture in the form of a tablet or powder.

  • The capsule is placed in a machine that breaks the membrane that divides the two sections of the capsules. Thus, all the ingredients are mixed. Mixing the amalgam helps the dentist avoid direct contact with mercury or excessive mercury vaporization.
  • The dentist collects the mixture and places it on the prepared cavity. Remember, the mixture is now available in the form of a thick paste.
  • Some amount of mercury in the filling rises above when it is being pressed inside the cavity. This is important to make the filling stronger. Nevertheless, the dentist will remove the excess mercury as much as possible. 
  • The filling will start to get hard almost instantly. But the mercury inside the filling reacts slowly. So, the entire filling may take some time to get dry and set properly.

The Amalgam Fillings Process

The process of placing amalgam fillings consists of multiple steps. 

  • After a thorough assessment, your dentist will locate the decayed area and use local anesthesia to numb the area.
  • Now, the decay in the area for treatment will be removed with a drill, laser, or air abrasion instrument. Make a note that the dentist will choose the instrument according to their comfort level, expertise, area of decay, and the severity of the condition. 
  • Once the decay is removed, the dentist will check the area to ensure proper removal. 
  • Next, the dentist will remove the debris and bacteria cavity from the decayed area. 
  • If the decay is around the root of your affected tooth, the dentist will first protect the nerve by applying a linear film of the filling solution.
  • Then, the amalgam fillings will be poured inside the cavity, and the dentist will finish and polish the fillings.

Throughout the procedure of preparing the fillings and setting them, a dentist has to follow the set of guidelines from the FDA. 

Benefits Of Amalgam Fillings

The American Dental Association has termed dental amalgam fillings “safe, strong, and affordable” in its journal. Let’s find out why these are beneficial dental restorative solutions. 

Less Expensive

If you want the most pocket-friendly option for fixing the cavities or decays in your teeth, amalgam fillings are the best choice. The longer shelf life of these fillings further ensures that you do not need to get the cavities filled in short intervals.

Further, it is a single-visit restorative solution, saving you from the hazard of visiting your dentist again and again. 


Made of different metals, these fillings have a reinforced structure. So they easily don’t get damaged or broken. Usually, these fillings last around ten to fifteen years. 

Ideal For Major Tooth Decay

When there are big cavities in your teeth or they are majorly damaged, amalgam fillings will be the best solution. With a reinforced structure, these fillings can easily restore the damage. 

Works For Heavy-Duty Teeth

Silver amalgam fillings are done in the teeth at the back. These teeth are majorly responsible for chewing food. As these fillings are made of metal, they can remain undamaged even after chewing the hard food items.

However, you cannot have hard food immediately after getting these fillings done. You have to give them at least 7-15 days of time so that they can get set properly and withstand grinding hard food items. 

If you are having problems biting food after these fillings, consult your dentist or an orthodontist

Offers Protection From Cavities In The Future

If you are prone to having cavities in your teeth, you can largely benefit from amalgam fillings. When these fillings are done on a tooth, the surrounding areas become stronger and thus prevent future formation of cavities. 

A Trusted Solution For Around 200 Years

For around 200 years, dentists have been recommending and doing amalgam fillings to fight tooth decay and cavities. It must be a safe and effective solution to stay relevant for so long. 

Despite various concerns and studies about toxicity caused by various metals, especially mercury, these fillings have emerged as safe and effective solutions. 

Solidifies Fast

Dental amalgam fillings are easily placed and need less preparation than other filling solutions. For instance, when a dentist does composite fillings, they must wait until the filled area becomes completely dry. In addition, these fillings become hard quickly.

So, these are preferred solutions by dentists for the treatment of children or individuals with special needs. 

Overall, dental amalgam fillings do not come off easily, and they are easy to place and less expensive as a dental restorative solution. 

Disadvantages Of Amalgam Fillings

Amalgam fillings are preferred by many as they are pocket-friendly and come with a longer shelf life than other alternatives. Still, there are some drawbacks to this dental restorative solution.


Amalgam fillings are silver in color and interfere with the teeth’s natural appearance. So, these fillings are not used for the restoration of teeth at the front.

Contraction And Expansion In Contact With Heat And Cold

Made of mercury, zinc, copper, tin, and silver, these fillings respond to contact with cold and heat. If these fillings come in contact with cold, they will contract and cause leakage. At the same time, they will expand in the heat.

When expansion or contraction happens, your dental structure can be damaged, and the fillings can break or leak. 

Corrosion And Leakage Of Dental Fillings

The amalgam dental fillings can leak, and over time, there can be corrosion in the fillings. The fillings’ metals can oxidize, causing discoloration or the teeth’ grey/black appearance. Corrosion may also result in the early decay of these fillings. 

These Can Cause Tooth Staining

Amalgam fillings can cause staining on your teeth, and the stain removal procedure is also quite critical. Your dentist will need to remove the fillings quickly and then help you remove stains.

So, if you are concerned about the appearance of your teeth or have plans for teeth beautification/whitening services, look for alternative dental fillings. 

Your Teeth May Become Weak With Dental Amalgam Fillings

Your dentist will remove portions of some tissues in your tooth before the amalgam filling is done. This procedure can damage the structure of your tooth and weaken it. 

Teeth Sensitivity Can Happen With Amalgam Fillings

The metals in the amalgam fillings will react when you are having extremely hot or cold food. So, with these fillings, your teeth can become more sensitive. 

Can Cause Allergic Reactions

If you are allergic to any of the components present in amalgam filling, you can experience local irritations or other allergic reactions. 

Amalgam Fillings Side Effects

To understand the side effects of amalgam fillings, you need to know about the possibility of toxicity caused by the essential elements of these fillings.

Effects Of Silver In Dental Amalgam Fillings

Silver has multiple medical properties. However, the silver present in the amalgam fillings can cause local irritations. So, if you experience any irritation around the teeth with amalgam fillings or you have hypersensitivity, you must avoid these fillings.

Effects Of Mercury In Dental Amalgam Fillings

The elemental mercury used in amalgam dental fillings exposes you to a very low level of mercury vapor inhalation or mercury ingestion. Still, if you are hypersensitive to mercury or already have some neurological medical history, you can experience tremors, nausea, and muscle twitching. 

Effects Of Zinc In Dental Amalgam Fillings

Zinc does not yield any harmful effects unless you are ingesting it in large amounts. Still, if you are facing stomach upset immediately after the dental amalgam fillings, consult your doctor, as the zinc in the filling may be responsible for that.

Effects Of Copper In Dental Amalgam Fillings

The copper in the fillings is not harmful, but sometimes excessive exposure to copper can cause kidney problems and anemia. However, no clinical study has established how the copper in amalgam fillings can cause this.

Effects Of Tin In Dental Amalgam Fillings 

The dust and fumes of tin can cause problems in your lungs. Excessive consumption of this metal can also make you feel nauseous and upset your stomach. 

Amalgam Fillings Vs. Composite Fillings

Amalgam and composite dental fillings are single-visit treatments to remove tooth decay and cavities. However, these are different in many aspects. The table below explains.

DifferenceComposite Dental FillingsAmalgam Dental Fillings
MaterialResin50% elemental mercury, silver, tin, zinc, and copper
AppearanceNaturalSilver-like appearance
Bioaccumulation and mercury toxicity Not applicableThough no or little clinical evidence is available, bioaccumulation and mercury toxicity can happen in amalgam dental fillings.
DurabilityAround five to seven yearsAround ten to fifteen years
CustomizationPossibleNot Possible
Ideal ForSmall tooth restorations and filling up small cavitiesFixing high risks of tooth decay
PriceAround $130-480Around $150-300

People prefer amalgam fillings over composite fillings because they get solidified easily, and they offer a more durable solution at a lower price.

However, if you want a customized or more natural-looking solution and are at a higher risk of getting affected by mercury toxicity, you must go for composite fillings. 

Concerns Regarding Amalgam Fillings Removal

Removing or replacing amalgam fillings is only recommended when the fillers are broken or there is no damage beneath these fillings. Also, if you are hypersensitive to mercury or have suddenly developed mercury allergies, you may need the removal of these fillings.

Otherwise, removing these fillings can cause unwanted health problems. A small amount of mercury vapor is released at the time of amalgam fillings removal. So, there is no need to ingest or inhale more mercury unnecessarily. Especially if you are pregnant or a lactating mother, you must avoid the removal or amalgam fillings unless there is a dire necessity.

In addition, unnecessary removal of amalgam fillings from the teeth can cause damage to your tooth structure.

Mercury Amalgam Fillings: Addressing The Safety Concerns

Dental amalgam fillings have mercury, and mercury vapor is formed when the fillings are done or removed. We can consume a small amount of mercury as we chew food with teeth having amalgam fillings. So, how safe are these fillings, and are we at a more significant risk of mercury toxicity with these fillings?

The association of mercury toxicity with dental amalgam fillings has been looked into since the 1990s. And the latest ruling regarding these dental fillings with mercury came in 2009. 

The FDA classified these fillings as class II devices, which are known to have more associated risks. The FDA further came up with a “special controls guidance document” for amalgam fillings.

To explain further, the FDA ensures the reasonable safety and efficacy of these fillings

But at the same time, it asks these devices must have labeling to explain the process of application and warnings for the dentists

The good news is that the Centers for Disease Control and Prevention (CDC) also issued a report in 2001. 

In that report, the CDC highlighted the lack of evidence regarding the association of dental amalgam fillings with compromised health of people and the health benefits of removing amalgam fillings

Amalgam Fillings And Bioaccumulation 

The Agency for Toxic Substances and Disease Registry has a complete mercury overview that says that bioaccumulation of mercury can cause damage to our nervous system and many other vital body functions. 

Now, what is bioaccumulation? When a particular chemical gets stored in the organs and tissues of our body in an increased amount, it is called bioaccumulation. 

Mercury, one of the main components in dental amalgam fillings, can cause bioaccumulation. Though the major part of the mercury entering our bodies through food or amalgam fillings is eliminated, some parts can remain to cause storage in tissues, fluids, and organs.

The kidney and brain are the two organs that are most likely to get affected by this bioaccumulation. However, more studies need to be done to establish the bioaccumulation of mercury caused by dental amalgam fillings and related harmful effects on specific organs.

Are Amalgam Fillings Safe For Everyone?

No, amalgam fillings are not safe for everyone, as the FDA has identified certain populations to be at a higher risk from amalgam fillings because of the mercury present in them. The mercury in the fillings can get evaporated with time, and that can affect the brain or kidney. Especially young children and fetuses are at a higher risk of suffering from the neurotoxic effects of mercury vapors.

Honestly, there is not enough clinical data to establish how and why the mercury in dental amalgam fillings has caused brain or kidney damage. But still, if you belong to any of the groups mentioned below, you must avoid getting dental amalgam fillings and look for alternative restorative solutions like resin fillings or ionomer glass cement fillings. 

  • People who are allergic to mercury, tin, zinc, copper, and silver in dental amalgam fillings
  • Anyone with a history or ongoing condition of neurological diseases
  • People with kidney diseases or kidney impairments
  • Lactating mothers 
  • Newborns, infants, or children below six years of age
  • Women who are trying to conceive
  • Pregnant women

Further, don’t forget to check for hypersensitivity with the materials present in other fillings also. 

How To Take Care Of Amalgam Fillings?

Amalgam fillings remain durable only when you take care of them properly. Your dentist will explain all the care tips to you. You can also follow the methods mentioned below for proper care.

Be Gentle While Brushing Or Flossing Your Teeth

When you have got dental amalgam fillings in your teeth, you must use brushes with soft bristles and make the movement around your teeth very gentle. 

Don’t Wash Your Mouth With Toothpastes And Mouthwashes Having Alcohol

Once you have amalgam dental fillings, you need to use toothpaste for sensitive teeth or the ones prescribed by your dentist.

Never use mouthwash or toothpaste with alcohol for cleaning your teeth, as alcohol can give ugly stains on your teeth or make the fillings decay. 

Be Mindful, And Don’t Keep Your Filled Teeth Busy

Local anesthesia is used when amalgam fillings are done. So, even after the fillings are done, it will take some time for you to regain consciousness in that area. 

But during that period, you have to be mindful so that you do not end up damaging the amalgam fillings. Do not bite your nails or do not touch the filled teeth with your tongue. Also, make sure that your filled teeth are not grounded or clenched. 

For the first day, it is always better to have liquid or semi-liquid food and try to use the teeth on the opposite side while having your food.

From the next day, you can have soft food that will not upset the filled teeth. Be a little careful with what you eat for at least a week to protect your dental amalgam fillings. Avoid food items that are hard, sticky, and chewy. 

Avoid Food That Is Extremely Cold Or Hot

If you think that dental treatment always calls for treating an ice cream, you will be disappointed with dental amalgam fillings. If you have just got your amalgam fillings done, having something very cold will cause contraction in the fillings, and thus they can get leaked or cracked.

Similarly, the fillings can get damaged if you have extremely hot food, causing expansion. When the fillings get damaged, your teeth will become sensitive, and you will feel sharp pain.

You have to keep in mind that amalgam fillings are a combination of various metals like zinc, copper, mercury, silver, and tin. Metals always respond more to changes in temperature.

Don’t Undermine The Importance Of Regular Checkups

When you have just got your amalgam fillings done, you must not miss the follow-up checkups. There may not be some apparent issues with your teeth, but checkups are important to ensure no leakage or damage is there in the fillings.

If there are issues with your dental fillings, the dentist will fix them so that the fillings become long-lasting. Even the most minor crack in the filling can cause sensitivity in your teeth. So, it is always recommended to get the cracks and leakages in the fillings fixed at the earliest possible. 

The Takeaway

Dental amalgam fillings are one of the most durable and least expensive solutions to get rid of cavities and tooth decay. If the fillings are done right, and you take care of your teeth properly, they will last for around fifteen years. 

If you have a dental cavity or some other issues in your teeth, consult your dentist regarding the efficacy of amalgam fillings and their side effects. Also, compare whether other restorative solutions like composite or resin fillings will be more suitable for you. 

Usually considered safe, these amalgam dental fillings may not be ideal for you if you are pregnant, a lactating mom, and someone with kidney and neurological health problems. So, if you belong to the risk groups determined by the FDA, you must consult your dentist and seek alternative solutions. 

Finally, to enjoy the best results with your dental fillings, you must be particular about your diet, dental checkups, and oral hygiene. 

Frequently Asked Questions (FAQs)

Are Amalgam Fillings Better Than Composite Fillings?

Yes, amalgam fillings are better than composite fillings in terms of durability. 

However, if you are concerned about the appearance of your teeth, composite fillings will be a better choice. 

Resin is used in dental composite fillings, which give your teeth a natural appearance. So, many people prefer composite filling for their teeth at the front and back. On the other hand, amalgam fillings can get discolored with time due to oxidization, ruining the overall appearance of your teeth.

Amalgam fillings are also known to interfere with the natural structure of your teeth. So, it is always better to consult a dentist who will help you get the best dental fillings according to the condition of your teeth. 

How Long Should Amalgam Fillings Last?

Amalgam fillings are very popular because of their durability. If fillings are done properly, and you are particular about the care regime, your dental amalgam fillings will last for around 15 years.

But if there is clenching or grinding in your teeth, replacing amalgam fillings will be required on an urgent basis.

Do Amalgam Fillings Cause Mercury Poisoning?

Mercury is a substance present in air, water, and soil. Dental amalgam fillings also have mercury. Yes, mercury is harmful to human beings, and with time, your dental amalgam fillings will release mercury in certain amounts. However, no clinical evidence exists to prove how amalgam filling causes mercury poisoning.

Still, you must remain aware of mercury poisoning and its symptoms like muscle twitching, weakness, tremors, metallic taste in the mouth, and nausea. Once you feel any of the symptoms, you must consult your dentist immediately.

Are Amalgam Fillings Safe?

Yes, amalgam fillings are safe. The U.S. Food & Drug Administration says that when one has multiple dental amalgam fillings, they are found to have slightly elevated levels of mercury in their urine or blood. However, the mercury levels usually remain within the safe level.

The FDA further says that there is no “conclusive evidence” showing the harmful effects of mercury on people with dental amalgam fillings.

Does The Wastage Of Dental Amalgam Fillings Harm The Environment?

If mercury amalgams are not disposed of properly, they can have major impacts on the environment. Mercury can get deposited in landfills, water reserves, and even in the air, making humans and animals subject to mercury poisoning. 

However, to avoid or minimize the environmental impacts of dental amalgam filling wastage, most dental offices use a filtration system. The filtration system helps to cut down the amount of solid mercury being passed into the sewer system. 

These offices also use amalgam separators, which are used to isolate the components of the amalgam and discharge mercury into wastewater. 

The American Dental Association has come up with a set of “handling and disposal practices” for amalgam wastage. 

Are Amalgam Fillings Safe During Pregnancy?

You should not go for amalgam fillings or the removal of amalgam fillings if you are pregnant, trying to conceive anytime soon, or a nursing mother. The amalgam can release mercury vapor at the time of placing or removing these amalgam fillings. 

The mercury vapor can get absorbed into your bloodstream within as little as 30 hours, and for a pregnant mother, the transfer of mercury to the fetus will happen through the umbilical cord blood. 

Similarly, for lactating mothers, bioaccumulation of mercury can happen in the breast milk through dental amalgam fillings. So, lactating infants and children can be exposed to mercury, inviting adverse health effects. 

Though there are not enough clinical studies to establish the association of mercury toxicity and adverse health effects on fetuses and infants caused by amalgam fillings, the U.S. Food & Drug Administration or FDA has included pregnant and nursing mothers, women trying to conceive, infants and children below six years in the risk group. 

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